If you define "coolest" as the most aesthetically stunning and culturally vibrant, the town of Deià in the Serra de Tramuntana mountains is the undisputed winner. This idyllic village has long been a haven for artists, writers, and celebrities, offering a "bohemian luxury" vibe that feels worlds away from the crowded beach resorts of the south. The architecture consists of honey-colored stone houses perched on steep cliffs overlooking the Mediterranean. For a more "hidden" cool, head to Cala Tuent, a remote pebble beach accessible via a winding mountain road that offers crystal-clear water and a total escape from mass tourism. If you mean "coolest" in terms of temperature, the Coves del Drach (Caves of the Drach) in Porto Cristo stay a constant, refreshing 21°C year-round, featuring one of the largest underground lakes in the world. Finally, the "Santa Catalina" neighborhood in Palma is the island's trendiest spot for foodies, filled with vermouth bars, vintage shops, and a bustling indoor market that represents the modern, cosmopolitan side of Mallorcan life.